Air control dampers are well known in the art. However, many of the dampers in use today were developed when the cost of energy was low. Consequently, there was less of a requirement for the dampers to seal tightly when in a closed position. With the rising energy costs, various seals and modifications have been made to existing damper systems in an effort to reduce fluid flow leakage.
Most of the seals and modifications rely on precise alignment of the various working parts. Unfortunately, manufacturing procedures often do not produce parts satisfying the degree of alignment required. In addition, precise alignment often depends on the assembly skills of those installing the systems. Consequently, once installed, damper systems often have leakage rates which are much greater than expected.
An example of current damper assemblies is U.S. Pat. No. 3,084,715 to Scharres which discloses damper blades having compressible hollow edges. For proper operation, the blades are preferably in an "opposed blade" arrangement wherein the blades are aligned edge to edge. Thus, the blades must be carefully installed so they are aligned edge for edge upon completion of the pivoting motion.
In yet another example of current damper systems, U.S. Pat. No. 3,547,152 to Hess discloses a damper having hollow rectangular blades with flexible, inflatible tubes along the edges or tips thereof. Once again, the blades are preferrably in an "opposed blade" position so as to provide an airtight seal when the damper assembly is closed. Furthermore, the ends of the blades include moveable extensions which require air pressure so as to be forced outwards against the damper side frame to effectuate a seal.
U.S. Pat. No. 3,771,559 to Alley also discloses the edges of the damper being forced into an "opposed position" so as to provide an effective seal when the damper assembly is closed. In addition, the blades are shown as having structural members on the inside thereof which make it difficult to insulate the blades so as to conserve even more energy.
The present invention solves these and many other problems associated with current damper systems.